Influence of respiratory motion correction on quantification of myocardial perfusion SPECT.

BACKGROUND

Respiratory-related cardiac motion could have considerable effects on myocardial perfusion imaging, leading to misinterpretation of the images. In this study, we examined the influence of respiratory correction on ECG-gated myocardial perfusion SPECT (RC-GSPECT) concerning regional myocardial perfusion and function.

MATERIALS AND METHODS

Using the NCAT phantom, a typical torso phantom was generated. SimSET, a Monte Carlo simulator, was used to image the photon emerging from the phantom. Twenty-six patients underwent a 2-day stress-rest ECG-gated myocardial perfusion SPECT (GSPECT) imaging. A separate study was also performed by simultaneous respiratory and cardiac triggering with the real-time position management (RPM) for respiratory correction (RC).

RESULTS

In simulation study, count density in the inferior and inferoseptal walls increased in the lower bin of the respiratory cycle. On the other hand, there was a higher correlation between RC-GSPECT and echocardiography for left ventricular ejection fraction (LVEF) (r = 0.95, P < .01 vs r = 0.88, P < .01 for GSPECT).

CONCLUSION

We proposed a new approach for respiratory and cardiac-gated SPECT to eliminate respiratory motion artifacts. RC-GSPECT is a feasible method in MPI studies and may play an important role to improve the quality of MPI images, particularly in the inferior wall.